For certains domains `nslookup` gives me a `Non-authoritative answer` section. What does this mean?
```
Got answer:
HEADER:
opcode = QUERY, id = 3, rcode = NXDOMAIN
header flags: response, want recursion, recursion avail.
questions = 1, answers = 0, authority records = 1, additional =
QUESTIONS:
www.example.com.SME, type = AAAA, class = IN
AUTHORITY RECORDS:
-> (root)
ttl = 1787 (29 mins 47 secs)
primary name server = a.root-servers.net
responsible mail addr = nstld.verisign-grs.com
------------
Non-authoritative answer:
------------
------------
Name: example.com
Address: 93.184.216.34
Aliases: www.example.com
```
DNS - NSLOOKUP : que signifie la réponse non autoritaire ?
Re: DNS - NSLOOKUP : que signifie la réponse non autoritaire ?
Fondamentalement, c'est what le name says it is. An authoritative answer comes depuis a nameserver that is considered authoritative for le domain qui c'est returning a record for (one of le nameservers in le list for le domain you did a lookup on), et a non-authoritative answer comes depuis anywhere else (a nameserver pas in le list for le domain you did a lookup on).
C'est basically a distinction entre a nameserver c'est an official nameserver for le domain you're querying, et a nameserver that isn't. Nameservers that ne sont pas authoritative are getting leur answers second (or third ou fourth...) hand - juste relaying le information along depuis somewhere else.
So, par exemple, If I did an nslookup of `maps.google.com` right now, I would get a response depuis one of mon configured nameservers. (Either depuis mon ISP, ou mon domain.) It would come back as non-authoritative parce que ni mon ISP's nameservers, nor mon own are in le list of nameservers for `google.com`. They ne sont pas Google's nameservers, so they're pas le authoritative source that creates le NS records.
The list of authoritative nameservers for Google is ci-dessous (from whois.internic.net).
>
Domain Name: GOOGLE.COM
Registrar: MARKMONITOR INC.
Whois Server: whois.markmonitor.com
**Name Server: NS1.GOOGLE.COM**
**Name Server: NS2.GOOGLE.COM**
**Name Server: NS3.GOOGLE.COM**
**Name Server: NS4.GOOGLE.COM**
Updated Date: 20-jul-2011
Creation Date: 15-sep-1997
Expiration Date: 14-sep-2020
If I changed mon configured DNS server to one of le ones in that list, et alors did an `nslookup` against `maps.google.com`, J'aimerais get an authoritative answer back. Those servers are le authority, (or source) for what are valid names in Google's domains, et what aren't. All autre nameservers, non-authoritative nameservers, get leur NS records depuis le authoritative servers somewhere down le line.
C'est basically a distinction entre a nameserver c'est an official nameserver for le domain you're querying, et a nameserver that isn't. Nameservers that ne sont pas authoritative are getting leur answers second (or third ou fourth...) hand - juste relaying le information along depuis somewhere else.
So, par exemple, If I did an nslookup of `maps.google.com` right now, I would get a response depuis one of mon configured nameservers. (Either depuis mon ISP, ou mon domain.) It would come back as non-authoritative parce que ni mon ISP's nameservers, nor mon own are in le list of nameservers for `google.com`. They ne sont pas Google's nameservers, so they're pas le authoritative source that creates le NS records.
The list of authoritative nameservers for Google is ci-dessous (from whois.internic.net).
>
Domain Name: GOOGLE.COM
Registrar: MARKMONITOR INC.
Whois Server: whois.markmonitor.com
**Name Server: NS1.GOOGLE.COM**
**Name Server: NS2.GOOGLE.COM**
**Name Server: NS3.GOOGLE.COM**
**Name Server: NS4.GOOGLE.COM**
Updated Date: 20-jul-2011
Creation Date: 15-sep-1997
Expiration Date: 14-sep-2020
If I changed mon configured DNS server to one of le ones in that list, et alors did an `nslookup` against `maps.google.com`, J'aimerais get an authoritative answer back. Those servers are le authority, (or source) for what are valid names in Google's domains, et what aren't. All autre nameservers, non-authoritative nameservers, get leur NS records depuis le authoritative servers somewhere down le line.